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Sunday, December 1st, 2024
| Time | Event | ||||
| 8:16a | [Botany • 2022] Euphorbia xiangxiui (Euphorbiaceae, subgenus Esula) • A Remarkable New Species from Jiufeng Mountains in Fujian Province, Eastern China
Abstract Euphorbia xiangxiui, a new species of Euphorbiaceae from Eastern China, supported by morphological and molecular evidence, is illustrated and described here. It can be distinguished from its closest relatives by the combination of several characters, including taller stature (up to 1.6 m), leaves of 5‐18 × 0.6‐3 cm in size, color of primary involucral leaves and cyathophylls changing from pink to rose, fading to green after fruiting, and four to six reniform-rounded concave glands. The molecular phylogenetic analysis, based on combined nuclear ribosomal ITS and plastid ndhF sequences, further supports that E. xiangxiui should be placed in the East Asian Clade of Euphorbia subg. Esula sect. Helioscopia. Keywords: Euphorbia xiangxiui; Flora of China; leafy spurges; phylogeny; taxonomy   Euphorbia xiangxiui N.Wei, Q.Yu, G.X.Chen & Q.F.Wang Yu, Qun; Chen, Guo-Xing; Yang, Yi; Wang, Qing-Feng and Wei, Neng. 2022. A Remarkable New Species of Euphorbia section Helioscopia (Euphorbia subgenus Esula, Euphorbiaceae) from Jiufeng Mountains in Fujian Province, Eastern China. Systematic Botany. 47(1); 259-267. DOI: doi.org/10.1600/036364422X16442668893265 https://www.cas.cn/syky/202204/t20220412 | ||||
| 8:30a | [Paleontology • 2024] Digestive Contents and Food Webs Record the advent of Dinosaur Supremacy
Abstract The early radiation of dinosaurs remains a complex and poorly understood evolutionary event. Here we use hundreds of fossils with direct evidence of feeding to compare trophic dynamics across five vertebrate assemblages that record this event in the Triassic–Jurassic succession of the Polish Basin (central Europe). Bromalites, fossil digestive products, increase in size and diversity across the interval, indicating the emergence of larger dinosaur faunas with new feeding patterns. Well-preserved food residues and bromalite-taxon associations enable broad inferences of trophic interactions. Our results, integrated with climate and plant data, indicate a stepwise increase of dinosaur diversity and ecospace occupancy in the area. This involved (1) a replacement of non-dinosaur guild members by opportunistic and omnivorous dinosaur precursors, followed by (2) the emergence of insect and fish-eating theropods and small omnivorous dinosaurs. Climate change in the latest Triassic resulted in substantial vegetation changes that paved the way for ((3) and (4)) an expansion of herbivore ecospace and the replacement of pseudosuchian and therapsid herbivores by large sauropodomorphs and early ornithischians that ingested food of a broader range, even including burnt plants. Finally, (5) theropods rapidly evolved and developed enormous sizes in response to the appearance of the new herbivore guild. We suggest that the processes shown by the Polish data may explain global patterns, shedding new light on the environmentally governed emergence of dinosaur dominance and gigantism that endured until the end-Cretaceous mass extinction.   Martin Qvarnström, Joel Vikberg Wernström, Zuzanna Wawrzyniak, Maria Barbacka, Grzegorz Pacyna, Artur Górecki, Jadwiga Ziaja, Agata Jarzynka, Krzysztof Owocki, Tomasz Sulej, Leszek Marynowski, Grzegorz Pieńkowski, Per E. Ahlberg and Grzegorz Niedźwiedzki. 2024. Digestive Contents and Food Webs Record the advent of Dinosaur Supremacy. Nature. DOI: doi.org/10.1038/s41586-024-08265-4 | ||||
| 9:11a | [Crustacea • 2024] Stenasellus stygopersicus • A Second Species of Stenasellus Dollfus, 1897 (Isopoda: Stenasellidae) from sulfidic groundwater of Iran described using morphological and molecular methods
Abstract We report on a new species of Stenasellus Dollfus, 1897 (Isopoda, Stenasellidae) from groundwater of Iran. Stenasellus stygopersicus Jugovic, Malek-Hosseini & Issartel sp. nov. inhabits the Chah Kabootari Cave that is adjacent to the Tashan Cave, the type locality of the first recorded species of Stenasellidae from Iran, Stenasellus tashanicus Khalaji-Pirbalouty, Fatemi, Malek-Hosseini & Kuntner, 2018. Both caves are fed by sulfidic groundwater and belong to the Tashan-Chah Kabootari species-rich aquifer on the Zagros Mountains. Both species are characterized by a large body size (≥ 20 mm), a female-biased sexual size dimorphism, and a distinct black-pigmented Bellonci’s organ. Stenasellus stygopersicus differs from S. tashanicus by a short and wide protopodite of pleopod I, setae set essentially along the apical margin of pleopod I exopodite, the subequal length and width of the male pleopod II protopodite, and deeply bilobed endopodites of pleopods III–V. Molecular evidence suggests that while Stenasellus stygopersicus is sister to S. tashanicus, the species are genetically distinguishable, with divergence time estimates ranging from 23 to 39.8 Ma. Keywords: biodiversity, phylogeny, Stenasellidae, groundwater, sulfidic cave
Order Isopoda Latreille, 1816 Superfamily Aselloidea Latreille, 1802 Family Stenasellidae Dudich, 1924 Genus Stenasellus Dollfus, 1897  Stenasellus stygopersicus Jugovic, Malek-Hosseini & Issartel sp. nov. Diagnosis: Body dorsal smooth, pleotelson being barely longer than its width (about 1.1 its width), short antennula (in males with only up to 34 segments in flagellum), barely overreaching antennal peduncle ( Fig. 3 ). Antenna with minute squama, ultimate segment of mandible palp without setae ( Fig. 3 ). Short and wide (length <width) protopodite of pleopod I, setae only along mesiodistal margin of pleopod I exopodite ( Fig. 5 ). Pleopod II protopodite subequal in length and width, exopodite segment II with only about 10 (9–11) plumose setae; endopod of pleopods III–V in males distally deeply bifurcated (i.e. bifurcation overreaches half of endopodite III–V length). A species with strongly female-biased sexual dimorphism in body size. Etymology: The name of the new species is formed from the prefix ‘stygo’ (from ancient Greek ‘stýx’), a common prefix used to refer to groundwater dwelling animals, and the Latin word ‘persicus’ referring to Persia. Jure Jugovic, Mohammad Javad Malek-Hosseini, Colin Issartel, Lara Konecny-Dupré, Matjaž Kuntner, Yaser Fatemi, Jean-François Flot, Christophe J. Douady and Florian Malard. 2024. A Second Species of Stenasellus Dollfus, 1897 (Isopoda, Stenasellidae) from sulfidic groundwater of Iran described using morphological and molecular methods. European Journal of Taxonomy. 968(1); 256–274. DOI: doi.org/10.5852/ejt.2024.968.2733 | ||||
| 3:11p | [Herpetology • 2024] Morphological Evolution and Niche Conservatism Across A Continental Radiation of Australian Blindsnakes
Abstract Understanding how continental radiations are assembled across space and time is a major question in macroevolutionary biology. Here, we use a phylogenomic-scale phylogeny, a comprehensive morphological dataset, and environmental niche models to evaluate the relationship between trait and environment and assess the role of geography and niche conservatism in the continental radiation of Australian blindsnakes. The Australo-Papuan blindsnake genus, Anilios, comprises 47 described species of which 46 are endemic to and distributed across various biomes on continental Australia. Although we expected blindsnakes to be morphologically conserved, we found considerable interspecific variation in all morphological traits we measured. Absolute body length is negatively correlated with mean annual temperature, and body shape ratios are negatively correlated with soil compactness. We found that morphologically similar species are likely not a result of ecological convergence. Age-overlap correlation tests revealed niche similarity decreased with the relative age of speciation events. We also found low geographical overlap across the phylogeny, suggesting that speciation is largely allopatric with low rates of secondary range overlap. Our study offers insights into the eco-morphological evolution of blindsnakes and the potential for phylogenetic niche conservatism to influence continental scale radiations. Scolecophidia, niche conservatism, ecological niche model, nonadaptive radiation, reptiles, speciation   Sarin Tiatragul, Alexander Skeels, J Scott Keogh. 2024. Morphological Evolution and Niche Conservatism Across A Continental Radiation of Australian Blindsnakes. Evolution. 78(11); 1854–1868. DOI: doi.org/10.1093/evolut/qpae132 งานวิจัยเชิงประจักษ์หลายงานที่ศึกษาในพื้ |
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